Abstract：
ZZ-6A hammer drill uses hollow multiple-diameter drill for percussive drilling and bucket grab for slag discharge to realize high hole-forming efficiency, but pile forming course is complex and slag deposition at pile bottom is over thick; although the tubular drill of simplified hammer drill integrating excavation and slag discharge could reduce slag deposition at pile bottom, it spends over long time for hole forming. Therefore, the two hammer drills are combined together to realize hole-forming and pile-forming sequence and to be used in construction of group pile foundation on sand and pebble stratum. In this way, not only construction efficiency is improved, but also slag deposition at pile bottom is obviously reduced.
CHENG Wan-li,HUANG Ming-kui,NIU Xin-li. RESEARCH ON PERFORMANCE AND PILE-FORMING QUALITY OF
COMBINED HAMMER DRILL[J]. Architecture Technology, 2012, 43(8): 746-748.
